/*var bexp=require("./b")
console.log(bexp)
console.log(bexp.foo)
console.log(bexp.add(10,20));
console.log(bexp.bstr);*/
function add(x,y){
    return x+y;
}
function jian(x,y){
    return x-y;
}
function chen(x,y){
    return x*y;
}
function chu(x,y){
    return x/y;
}
exports.add=add;
exports.jian=jian;
exports.chen=chen;
exports.chu=chu;